Corrosion-Induced Cracking in Reinforced Concrete due to Chloride Contamination and Ingress

In this study, accelerated steel corrosion tests on seven concrete prisms, 100 x 100 x 200 mm (3.94 x 3.94 x 7.87 in.) in size, embedded with reinforcing bar with D = 20 mm (0.79 in.) at cover thicknesses of 20 mm (0.79 in.) and 40 mm (1.57 in.) were carried out. Group A specimens were cast with sodium chloride in the mixture, and Group B specimens with no chloride initially were subjected to chloride ingress from the bottom or top surface during testing. The strain and surface crack width evolutions of concrete against corrosion time were studied. At the end of the test, the corrosion distributions were observed and examined with a three-dimensional (3-D) laser scanner. It was found that the corrosion distribution showed nonuniform behavior for the specimens with chloride ingress from the surfaces, while corrosion in the specimens with chloride added in were more uniform except for the pits near corrosion-induced cracks.